Technical Field
The present disclosure relates to the field of digital communication and, more specifically, to digital communication across multiple mediums.
Description of Related Art
The home networking technology family of standards developed under the International Telecommunication Union's Telecommunication Standardization sector (ITU-T G.hn) and IEEE P1905.1 standards describe a home networking environment in which multiple types of mediums may be used for communications. In both standards, access to each medium requires a complete medium specific transceiver. Bridging between mediums is performed using a switching function that is based on Ethernet or another protocol. In the device 100 shown in FIG. 1, the transceivers A, B and C are made up of a Data Link Layer (DLL) and physical layer (PHY) interface in accordance with the Open Systems Interconnection (OSI) model (ISO/IEC 7498-1) at the International Organization for Standardization. These transceivers can communicate with their respective mediums simultaneously.
In the case of the G.hn standard, the four supported medium types are power line, phone line, coaxial cable (baseband and RF coax) and POF (plastic optical fiber). The device 100 shown in FIG. 1 could be used as a G.hn defined Inter-Domain Bridge (IDB). Domains are used in G.hn to group devices that can communicate using the G.hn PHY and DLL/MAC protocols under the direction of a Domain Master (DM). Since devices in the same domain are usually able to communicate directly by passing signals at the physical layer, a domain is typically composed of devices that are attached to the same medium. Therefore, an IDB can be used to connect different mediums in a G.hn network. The IDB bridging function can be accomplished using an IEEE 802.1 Ethernet switch or some other bridging function such as that defined by the P1905.1 standard. The switch could also provide an Ethernet interface to an application that was attached directly to the IDB device 100 as shown in FIG. 1.
With multiple domains and traffic across the multiple domains, inter-domain routing is required. Regarding inter-domain routing, routing loops can form when multiple IDBs are connected to different mediums in a home network. These loops can also occur when multiple IDBs connect between the same two mediums. Also, more complex loops can be formed between more than two mediums or more than two domains. Inside a single domain it is the DM's responsibility to prevent routing loops by defining the broadcast relay tree. However, when multiple domains are involved this approach would require complex interaction between the multiple DMs.